Lift dolly for use in conjunction with stand-mounted power tools and the like, including mounting mechanism

ABSTRACT

A lift dolly is provided for lifting and transporting stand-mounted power tools and the like, with little effort. The dolly includes a pair of platforms and a wheel system having at least three castors extending downwardly from the platforms. The dolly is designed such that one step onto a latching or locking mechanism by the operator causes the wheel system to be forced downward relative to the stand thereby slightly lifting the power tool and stand off of the ground and enabling transport of same via the castors. Another step on the locking or latching mechanism disengages the wheel system and permits gravity to return the stand and tool firmly to the ground for use.

This application is a Continuation-in-Part (CIP) of 08/795,409, filed onFeb. 5, 1997, now U.S. Pat. No. 5,876,173, and is also a CIP of Ser. No.08/880,864, filed Jun. 23, 1997, now U.S. Pat. No. 5,957,649, thedisclosures of which are hereby incorporated herein by reference.

This invention relates to a lift dolly which is adapted to lift andtransport stand-mounted power tools, and the like. More particularly,this invention relates to such a lift dolly which permits the operatorto lift the tool to be transported by simply stepping onto afoot-receiving surface thereby forcing the dolly's wheel system downwardrelative to the tool and into a position for supporting and transportingthe stand-mounted tool.

BACKGROUND OF THE INVENTION

Lift dollies are old and well-known in the art. Dollies have beenprovided which function to lift and move bulky machinery, plate glass,and the like. In such dollies, a hand actuated hydraulic jack typicallyraises and lowers forks for lifting the machinery after which the dollyand machinery may together be rolled along the floor/ground by way of apair of wheels mounted on the dolly.

Unfortunately, such dollies, while useful in transporting crates, plateglass, etc., are not adapted to lift and/or transport items such asstand-mounted power tools and the like due to the shape defined by legsof such stands.

In view of the above, it is apparent that there exists a need in the artfor a lift dolly capable of lifting and transporting, with littleeffort, stand-mounted objects, such as power tools. Preferably, such adolly should be simplistic, easy to use, and cost-effective tomanufacture. There also exists a need in the art to efficiently andeasily mount such a dolly to legs of a power tool stand.

It is a purpose of this invention to fulfill the above-described needsin the art.

SUMMARY OF THE INVENTION

Generally speaking, this invention fulfills the above-described needs inthe art by providing a dolly for selectively lifting and transporting apower tool mounted on a stand, the dolly comprising:

a first platform including a wheel system extending downwardlytherefrom, said first platform further including an actuation surfacefor receiving downwardly applied pressure in order to lift the stand andtool off of the ground;

a second platform including a wheel system extending downwardlytherefrom;

the first and second platforms being connectable to one another;

lift means for moving the dolly from a passive position to a liftposition thereby lifting the stand and power tool off of the ground andenabling the power tool to be moved on the ground via the wheel systems;and

a plurality of mounting brackets for mounting the platforms tocorresponding legs of the stand, each of the mounting brackets includingfirst and second sidewalls connected by an end wall, wherein the endwall includes an aperture defined therein for receiving a rigid memberof one of the platforms so that the rigid member can be pivotallyconnected to the bracket at a location between the first and secondsidewalls.

In certain preferred embodiments, each of the mounting brackets issubstantially U-shaped.

This invention still further fulfills the above-described needs in theart by providing a power tool device which may be selectivelytransported from one location to another along the ground, the powertool device comprising:

a stand having first, second, third, and fourth elongated legs;

a power driven tool mounted on the stand;

a lift dolly affixed to the stand, the lift dolly including a wheelsystem, and being able to define each of a passive and a liftingposition, the passive position being defined as when the stand is theprimary ground support for the tool and the lifting position beingdefined when the stand and tool are lifted off of the ground and thedolly is the primary ground support for the tool;

the dolly including a first rigid member affixed to the first and secondlegs of the stand, a second rigid member directly affixed only to thethird and fourth legs of the stand, and a selectively actuatedconnection defining a first state and a second state, the dolly being inthe passive position when said selectively actuated connection is in itsfirst state and the lifting position when said connection is in itssecond state;

an actuator for moving the connection from its first state to its secondstate to lift the stand and tool off of the ground and enable transportof the stand and tool via the wheel system; and

at least one mounting bracket for directly and pivotally affixing one ofthe rigid members to one of the legs, the mounting bracket includingfirst and second approximately parallel sidewalls which are connected byway of an end wall, the end wall defining an aperture therein forreceiving an end of the one rigid member, the end of the rigid memberincluding at least one aperture defined therein, and wherein a fastenerextends through the aperture in the end of the rigid member and alsoextends through apertures defined in the sidewalls to pivotally connectthe one rigid member to the mounting bracket, and wherein the mountingbracket is non-pivotally affixed to the one leg.

IN THE DRAWINGS

FIG. 1 is a perspective view of the lift dolly according to anembodiment of this invention, in its locked/lifting position.

FIG. 2 is a perspective view of the FIG. 1 dolly in itsunlocked/lowering position.

FIG. 3 is a right side elevational view of the dolly of FIGS. 1-2mounted to a stand which supports a table saw, the dolly beingillustrated in the unlocked position where the stand solely supports thesaw.

FIG. 4 is a fragmentary right side elevational view of the dolly ofFIGS. 1-3 mounted to the table saw stand of FIG. 3, the dollyillustrated in the locked position where the table saw and stand aresupported on the ground by the wheels so as to enable transport.

FIG. 5 is a front elevational view of the FIGS. 1-4 dolly mounted to thestand, illustrating the dolly in its unlocked position where the standcontacts the ground.

FIG. 6 is a fragmentary front elevational view of the FIGS. 1-5 dollymounted to the stand, illustrating the dolly in its locked and liftingposition where the stand is lifted from the ground and the stand and saware supported on the ground primarily by the wheels.

FIG. 7 is a perspective view of the latching/locking system used toconnect the first and second dolly platforms of FIGS. 1-6.

FIG. 8 is a perspective view of a dolly according to another embodimentof this invention.

FIG. 9 is a rear elevational view of part of the FIG. 7 latchingmechanism, illustrating the attachment of the biasing spring to the malelatch member.

FIG. 10 is a partial side plan view of another embodiment of thisinvention where the platforms of any of the aforesaid embodiments ofthis invention are mounted to legs of a stand-mounted power tool by wayof adjustable U-shaped members.

FIG. 11 is an exploded close-up perspective view of a U-shaped mountingmember of the FIG. 10 embodiment.

FIG. 12 is a perspective view of the U-shaped mounting member of FIG. 11being used to mount part of a platform to the leg of a stand inaccordance with the FIGS. 10-11 embodiment of this invention.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS OF THIS INVENTION

Referring now more particularly to the accompanying drawings in whichlike reference numerals indicate like parts throughout the severalviews.

Referring to FIGS. 1-7, it is seen that the lift dolly of the presentinvention, generally denoted by reference numeral 10, includes firstrigid platform 12 having proximal end 14 and distal end 16 and secondrigid platform 18 having proximal end 20 and distal end 22. Firstplatform 12 includes generally flat, triangular, and trapezoidal frameportion 24, including rigid elongated members 3-5, that may be open (asillustrated) or closed (e.g. a solid or quasi-solid metal sheet or thelike). The wheel system of first platform 12 may include, for example, afirst pair of castor stems 28, each having a castor 30 thereon, whichextend downwardly from frame 24 proximate distal end 16 of platform 12.Alternatively, other types of known wheels may be used in place ofcastors 30 to support lift dolly 10.

For example, the wheel system of each platform may simply include asingle elongated rotating cylinder [instead of the illustrated castors],so that only two wheels are provided on the entire device. It should benoted, however, that according to this cylinder-inclusive embodiment,the dolly would only be mobile in one direction as opposed to alldirections [this is, of course, acceptable in certain embodiments ofthis invention].

Referring to FIGS. 1, 2, 7, and 9, platform 12 further includes, as partof the latching mechanism, foot receiving surface or pedal 25 mounted ontop of respective ends of members 3 and 4, downwardly extending maleportion 48 of the latching mechanism that is pivotally mounted belowsurface 25, mounting member 47 affixed to one of members 3 or 4 (or toplate 25), and pivot axis 49 about which male portion 48 pivots relativeto mounting member 47.

Second platform 18 is smaller in size than platform 12, and includesgenerally flat, triangular, and trapezoidal frame portion 32, thatincludes rigid elongated members 6-9. Frame 32 may be open (asillustrated) or closed. A second pair of castor stems 34, each having acastor 30 thereon, extend downwardly from frame 32 proximate distal end22 and crossbar 9 thereof.

Platform 18 further includes, as part of the latch/lock assembly, rigidU-shaped member 50 that projects from the inner vertical surface ofcrossbar 9, vertically extending projection or cam surface 51 thatextends from the upper horizontal surface of crossbar 9, latchingaperture or void 52 (see FIG. 7) defined in the bottom surface ofU-shaped member 50, and locking crossbar 59 which locks the latchingmechanism by fitting into cutout or notch 58 of male member 48. Althoughthe cam surface is defined by projection 51 in the illustratedembodiments, this surface may be defined by other portions of platform18 or the female portion of the latching mechanism.

With regard to platforms 12, 18, and frames 24, 32 thereof, theplatforms illustrated in FIGS. 1-8 are open (i.e. they are made up ofthe frame, which includes a plurality of rigid members connected to oneanother at corners of the frame). However, it will be appreciated bythose of skill in the art that platforms 12 and 18 (as well as frames 24and 32) may be of any of a number of different shapes or designs,provided that the essential function of the dolly is not compromised.For example, each platform may be made up of a planar or arced sheet ofrigid material (e.g. sheet metal) that is void of any elongated framemembers. Furthermore, it will be appreciated that the illustrated anddiscussed latching mechanism is exemplary and the invention is notlimited thereto. Other known latching mechanisms which permit selectiveattachment of the platforms may instead be used.

Mounting members (or anchor plates) 38 are attached to the four cornersof dolly 10 for the purpose of affixing the dolly to the four legs ofthe stand 55 which supports an item such as power tool 57 (e.g. tablesaw). Other power tools such as drills, lathes, etc. may also be mountedon stand 55, as may objects other than power tools. For example, it hasfurther been found that the dolly 10 can be advantageously used inconnection with or built into a wide variety of other devices such astables, workbenches, medical equipment, chairs, engine lifts, filingcabinets, copiers and other office equipment to facilitate liftingand/or transport thereof. Each mounting member 38 is pivotally attachedto the corresponding platform and/or frame and is rotatable about avertical axis so that the platforms may be mounted to different sides oflegs of different sized stands 55.

In order to utilize lift dolly 10 to perform its intended function,first platform 12 is positioned proximate an object 55, 57 (e.g.stand-mounted power tool) to be lifted. Each mounting member or anchorplate 38 is secured to a different leg of object 55, 57. This securementcan be accomplished in any appropriate fashion, including insertion ofbolts attached to plates 38 through corresponding apertures defined inthe legs of stand 55.

Once anchor plates 38 of platform 12 are secured to object 55, 57, theweight of the object causes first platform 12 to be oriented so thatcastors 30 merely rest on the ground without supporting the object (i.e.while the wheels 30 may touch the ground or be slightly raisedtherefrom, the stand may not be moved as the legs are the primary toolsupport, and use of the tool is unaffected). See FIG. 3.

Second platform 18 is secured to the other end of object 55, 57 to belifted in a similar fashion to the securement of first platform 12 toobject 55, 57 (i.e. platform 12 is attached to first and second legs ofstand 55, while platform 18 is attached to third and fourth legs of thestand). When second platform 18 is secured, it is oriented with itsproximal end 20 terminating beneath first platform 12. See FIG. 3.

In order to lift object 55, 57 off of the ground in order to move it viathe dolly, downward pressure is exerted by an operator or user(preferably by the foot of the operator) on foot-receiving surface orplatform 25 proximate end 14 of frame 24. When end 14 of platform 12 ispressed downward, spring-biased male portion 48 is inserted throughaperture 52 (see FIG. 7) of the latch's female portion, with thespring-bias then causing the latching mechanism to lock the twoplatforms 12 and 18 together as cutout or notch 58 in male 48 receiveslocking member or crossbar 59 due to the biasing of male 48 towardlocking member 59 by spring 71 (see FIG. 9).

When crossbar 59 is locked in notch 58, castors 30 of both platformshave been forced downward and are held there contacting the ground in asupporting manner as shown in FIGS. 4 and 6, thereby lifting stand 55and tool 57 off of the ground so that they can be wheeled across theground and transported. As discussed, when rigid platform 12 is forceddownward by the operator, elongated members 3 and 4 engage end 20 andcrossbar 8 of second platform 18 thereby causing downward movement offrame 32 relative to the stand, and thus castors 30 of platform 18 alsobecome supportive of the stand and tool as shown in FIGS. 4 and 6. Whenthe first and second platforms are generally horizontal (e.g. see FIGS.4 and 6), the stand and tool are lifted off of the ground by all fourwheels or castors and are ready for lateral transport on the ground.

It is noted that the first pair of castor stems 28 may be longer thanthe second pair of castor stems 34 in order to assure level positioningof dolly 10, or alternatively one or both of frames 24 and 32 may bebent or curved to accomplish the same result.

In certain embodiments, platforms 12 and 18 are not secured to oneanother in any fashion, except via the legs of the stand, and by latchmechanism 47, 48, 49, 50, 51, 52, and 59 when it is locked. Thus, whendolly 10 is in its passive or non-lifting position (see FIGS. 2, 3, and5), the two platforms are not directly connected together in certainembodiments, although the bottom surfaces of members 3 and 4 rest uponthe top of crossbar 8 of platform 18, and the legs of stand 55indirectly couple the platforms.

When the operator presses down on surface 25, male 48 becomes lockedwithin the female portion 50, 52, 59 of the latch mechanism therebylocking the wheels or castors in their supporting position and, at thesame time, coupling the two platforms (see FIGS. 7 and 9 for a detailedview of the latch mechanism). When the wheels are in a supportiveposition and the latch is locked thereby coupling the platformstogether, stand 55 and tool 57 may be rolled along the ground andtransported.

In certain alternative embodiments, platforms 12 and 18 may be attachedto one another at a location in addition to the latching mechanism (e.g.at bar 8). However, regardless of whether the platforms are additionallyattached, they are to be selectively coupled via the latching mechanism.

FIG. 9 illustrates the attachment of biasing spring 71 to mountingmember 47 and male member 48 of the latching mechanism. Pins 72 areprovided for attaching spring 71 to these members so that spring 71biases member 48 toward crossbar 59 when the center of gravity of member48 is on the crossbar 59 side of axis 63, and away from crossbar 59 whenthe center of gravity of the male member is on the other side of axis63.

Referring to FIG. 7, when it is desired to lower the stand and tool fromits lifted position, the operator simply steps on surface 25 in order torelease the latch and allow gravity to lower the stand and tool to theground for use. When the operator steps on surface 25 when the latch islocked, male portion 48 is caused to move further downward throughaperture 52 in a manner so that upwardly angled surface 61 of member 48slides along the inner surface of crossbar 59. The sliding of angledsurface 61 of member 48 along crossbar 59 causes male member 48 to pivotabout axis 49 in a direction away from crossbar 59 and to the oppositeside of axis 63 that extends through each of members 47 and 48 and axis49.

When male member 48 reaches the other side of axis 63, the spring causesmember 48 to be biased in the opposite pivotal direction (i.e. away fromcrossbar 59 as viewed in FIG. 7) so that when the operator lifts his/herfoot off of surface 25, stand 55 falls to the ground as male member 48moves upwardly through aperture 52 and is biased away from crossbar 59.On its way upward away from aperture 52 and crossbar 59 during therelease/unlocking process, the side of member 48 opposite cutout 58contacts projection (or cam surface) 51 which causes member 48 to moveback to the crossbar 59 side of axis 63 so that when male member 48 isagain pressed downward through aperture 52, the spring will bias member48 toward crossbar 59 which will come to rest within cutout 58 therebylocking together the platforms of the dolly with the stand and tool inthe raised or lifted position.

FIG. 8 illustrates dolly 10 according to another embodiment of thisinvention. This embodiment is different than the previously describedembodiment(s) in that anchor plates 38 are replaced with crossbarmembers 81 and 82 which are part of frames 24 and 32, respectively. Thetwo platforms are attached to the four legs of stand 55 by way ofcrossbars 81-82, and the mounting apertures 83 defined therein. Boltsare fed through apertures 83 and the stand legs in order to mount thedolly to the stand. Furthermore, all other elongated members (3, 4, 6,7, and 8) of the frames or platforms are telescopic in this embodimentin order to allow the dolly to mount onto different sized stands 55 andtools 57. Thus, these telescopic elongated members each include an innerelongated member and an outer elongated member which are axiallyadjustable relative to one another in order to alter the lengths ofmembers 3, 4, 6, 7, and 8.

FIGS. 10-12 illustrate another embodiment of this invention where rigidplatforms 12 and 18 of any of the aforesaid embodiments of thisinvention are mounted to legs 55 of a stand-mounted power tool (e.g.table saw) by way of adjustable substantially U-shaped members 81instead of by plates 38. Four such U-shaped members 81 are typicallyprovided so that the platforms and rigid members 3, 4, 6 and 7 thereofcan be pivotally mounted to corresponding legs 55. One member 81 isutilized to mount a corresponding rigid member (3, 4, 6, or 7) to a leg55.

As shown in FIGS. 11-12, each leg 55 of the stand includes a hole oraperture pattern including at least four apertures 83, with each legincluding rigid angled portions 84 and 85 which form an angletherebetween of from about 50-90 degrees. The apertures 83 in elongatedangled portion 84 line up with and correspond with apertures 83 inelongated angled portion 85. Each substantially U-shaped member includessubstantially U-shaped bracket 87 which is fixedly connected toattaching members 89 via fasteners 91. Optionally, a vertically orientedelongated slot 93 may be provided in U-shaped bracket 87 so that theposition of one of fasteners 91 may be adjusted or varied. Eachattaching member 89 includes four mounting apertures defined therein,two for receiving fasteners 91 so that members 89 may be connected tobracket 87, and two 96 for receiving fasteners 98 so that members 89 maybe fixedly connected to a leg 55. Still further, each attaching member89 includes attachment portion 101 which has apertures 96 definedtherein, intermediate connecting portion 103, and portion 105 which hasthe apertures defined therein which receive fasteners 91. Intermediateportion 103 connects and interfaces portions 101 and 105. Intermediateportion 103 forms an angle of approximately 70-120 degrees with portion101. Intermediate portion 103 forms an angle of approximately 110-160degrees with portion 105.

Each bracket 87 includes opposing sidewalls 111 and 113 which areconnected by wall 115. Wall 115 defines an angle of approximately 80-100degrees with each of sidewalls 111 and 113. Sidewalls 111 and 113 areapproximately parallel to one another in certain embodiments. Anelongated aperture 117 is defined in end wall 115, with a correspondingrigid member 3, 4, 6, or 7 being received within aperture 117 so thatthe rigid member can be pivotally affixed to sidewalls 111 and 113 viaat least one fastener 119. The elongated axis of fastener 119 definesthe pivot axis about which the rigid member can pivot. In certainembodiments, fastener 119 may include nut 120 and bolt 121, although anytype of suitable fastener may be used. Each rigid member 3, 4, 6, and 7includes at least one aperture 123 defined therein proximate an endthereof, so that when the rigid member is inserted through an aperture117 and into the confines of bracket 87, fastener 119 may affix therigid member (3, 4, 6, or 7) to the bracket 87. In each connection,fastener is fed through corresponding side holes or apertures 125 whichare defined in each sidewall 111 and 113, and also through aperture 123which is located between the corresponding apertures 125. A plurality(e.g. three) of apertures are defined (e.g. in a line) in each sidewall111 and 113 so that the affixing position of the rigid member may beadjusted relative to the position of the leg 55. In such a manner, themounting assembly shown in FIGS. 10-12 may be used to enable dollies ofthis invention to be mounted on different sized stands having legs 55.

Still referring to the FIGS. 10-12 embodiment, while attachment members89 and U-shaped brackets 87 are illustrated as separate and independentcomponents, it is recognized that they could be integrally formed withone another or welded to one another in certain embodiments of thisinvention.

Once given the above disclosure, therefore, various other modifications,features, or improvements will become apparent to the skilled artisan.Such other features, modifications, and improvements are thus consideredto be a part of this invention, the scope of which is to be determinedby the following claims.

I claim:
 1. A dolly for selectively lifting and transporting a powertool mounted on a stand, the dolly comprising:a first platform includinga first wheel system extending downwardly therefrom, said first platformfurther including an actuation member for receiving downwardly appliedpressure in order to lift the stand and tool off of the ground; a secondplatform including a second wheel system extending downwardly therefrom;the first and second platforms being connectable to one another; liftmeans for moving the dolly from a passive position to a lift positionthereby lifting the stand and power tool off of the ground and enablingthe power tool to be moved on the ground via said first and second wheelsystems, said lift means being actuated when said downwardly appliedpressure is applied to said actuation member; and a plurality ofmounting brackets for mounting said platforms to legs of the stand, eachof said mounting brackets including first and second sidewalls connectedby an end wall, and wherein the end wall includes an aperture definedtherein for receiving a rigid member of one of said platforms so thatthe rigid member can be pivotally connected to the bracket at a locationbetween said first and second sidewalls, wherein said legs of the standcomprise rigid angled portions defining said legs, said rigid angledportions forming an acute angle with respect to a plane defined by thefirst and second sidewalls, said first and second sidewalls havingangled attachment members providing a substantially flush interfacebetween said mounting bracket and said rigid angled portions.
 2. Thedolly of claim 1, wherein each of said mounting brackets issubstantially U-shaped.
 3. The dolly of claim 1, wherein each of saidmounting brackets further includes a plurality of mounting aperturesaligned in a linear manner in each of said sidewalls so that a mountingposition of the rigid member can be adjusted relative to thecorresponding leg of the stand.
 4. The dolly of claim 1, wherein each ofsaid mounting brackets further includes a first attachment memberaffixed to said first sidewall and a second attachment member affixed tosaid second sidewall, and wherein said first and second attachmentmembers include apertures therein which enable the mounting bracket tobe connected to the corresponding leg by way of fasteners.
 5. The dollyof claim 4, wherein said end wall defines an angle of from about 80-100degrees with each of said first and second sidewalls in each bracket. 6.The dolly of claim 5, wherein rigid angled portions define V-shapedlegs, said first and second sidewalls having angled attachment membersproviding said substantially flush interface between said mountingbracket and said rigid angled portions.
 7. The power tool device ofclaim 6, wherein said attachment members are removably fastened to saidfirst and second sidewalls respectively, said attachment members beinginterposed between said first and second sidewalls and said one leg tothereby provide said substantially flush interface.
 8. A power tooldevice which may be selectively transported from one location to anotheralong the ground, the power tool device comprising:a stand having first,second, third, and fourth elongated legs; a power driven tool mounted onsaid stand; a lift dolly affixed to said stand, said lift dollyincluding a wheel system, and being able to define each of a passive anda lifting position, said passive position being defined as when saidstand is the primary ground support for said tool, and said liftingposition being defined when the stand and tool are lifted off of theground and said dolly is the primary ground support for said tool; saiddolly including a first rigid member affixed to said first and secondlegs of said stand, a second rigid member directly affixed only to saidthird and fourth legs of said stand, and a selectively actuatedconnection defining a first state and a second state, said dolly beingin said passive position when said selectively actuated connection is inits first state and in said lifting position when said connection is inits second state; an actuator for moving said connection from its firststate to its second state to lift said stand and tool off of the groundand enable transport of said stand and tool via said wheel system; and amounting bracket assembly for directly affixing one of said rigidmembers to one of said legs, said mounting bracket assembly includingfirst and second approximately parallel sidewalls which are connected byway of an end wall, said end wall having a window aperture definedtherein for receiving an end of said one rigid member such that end wallcircumscribes said window aperture, and said end of said rigid memberincluding at least one aperture defined therein, and wherein a fastenerextends through said aperture in said end of said rigid member and alsoextends through apertures defined in said sidewalls to connect said onerigid member to said mounting bracket, and wherein said mounting bracketis pivotally mounted to said one leg about a single rotational axis. 9.The power tool device of claim 8, wherein said connection includes alatching mechanism having a male portion mounted to said first rigidmember and a female portion mounted to said second rigid member.
 10. Thepower tool device of claim 8, wherein said legs of the stand compriserigid angled portions defining V-shaped legs, said first and secondsidewalls having angled attachment members providing a substantiallyflush interface between said mounting bracket and said rigid angledportions.
 11. The power tool device of claim 8, wherein said mountingbracket assembly comprises first and second attachment members removablyfastened to said first and second sidewalls respectively, said first andsecond attachment members being interposed between said first and secondsidewalls and said one leg to thereby provide said substantially flushinterface.